Many naturally occurring proteins and peptides are of great interest in research, medical, and industrial applications, but obtaining them in sufficient quantities from their natural hosts can be problematic because of low purity or natural abundance. Furthermore, engineering the proteins for altered or improved properties is all but impossible in most native hosts (e.g. insulin from pigs or cows). As a result, scientists have turned to recombinant protein expression in model organisms whose genetics can be manipulated to cause overexpression of proteins not natively found in the host.
For technical reasons, microorganisms like E. coli and S. cerevisiae are the preferred hosts for recombinant protein expression. However, because model microorganisms lack the protein folding machinery and regulatory mechanisms of the organisms from which most proteins of interest originate (e.g. mammals), proteins are often translated poorly or fold improperly from expression constructs (recombinant DNA molecules encoding the protein being produced and other elements necessary for expression), resulting in poor protein expression, solubility and ultimately low yield. There is thus an ongoing and unmet need for improved compositions and methods for improving recombinant protein production.